Chapter 48 The Biosphere Factors that Affect Distribution

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Chapter 48: The Biosphere

Chapter 48: The Biosphere

Factors that Affect Distribution • Geologic history • Topography • Climate • Species interactions

Factors that Affect Distribution • Geologic history • Topography • Climate • Species interactions

Biosphere • Sum total of the places in which organisms live • Includes portions

Biosphere • Sum total of the places in which organisms live • Includes portions of the hydrosphere, lithosphere, and atmosphere

Climate • Average weather condition in a region • Affected by: – amount of

Climate • Average weather condition in a region • Affected by: – amount of incoming solar radiation – prevailing winds – elevation

The Atmosphere • Three layers – Outer mesosphere – Middle stratosphere (includes ozone layer)

The Atmosphere • Three layers – Outer mesosphere – Middle stratosphere (includes ozone layer) – Inner troposphere (where air is warmed by the greenhouse effect)

Fig. 48 -2, p. 868

Fig. 48 -2, p. 868

Ozone Layer • Region 17 to 27 kilometers above sea level in the stratosphere

Ozone Layer • Region 17 to 27 kilometers above sea level in the stratosphere • Molecules of ozone absorb most layers of ultraviolet light • Protects living organisms from excess exposure to UV light

Warming the Atmosphere • Solar energy warms the atmosphere and sets global air circulation

Warming the Atmosphere • Solar energy warms the atmosphere and sets global air circulation patterns in motion Figure 48. 3 Page 868

Rotation and Wind Direction • Earth rotates faster under the air at the equator

Rotation and Wind Direction • Earth rotates faster under the air at the equator than it does at the poles • Deflection east and west Figure 48. 2 Page 868

Seasonal Variation • Northern end of Earth’s axis tilts toward sun in June and

Seasonal Variation • Northern end of Earth’s axis tilts toward sun in June and away in December • Difference in tilt causes differences in sunlight intensity and day length • The greater the distance from the equator, the more pronounced the seasonal changes

cold cool temperature warm temperature tropical (equator) tropical warm temperature cool temperature cold March

cold cool temperature warm temperature tropical (equator) tropical warm temperature cool temperature cold March 231/2º June December September Fig. 48 -4, p. 869

Fig. 48 -5 a, p. 869

Fig. 48 -5 a, p. 869

Fig. 48 -5 b, p. 869

Fig. 48 -5 b, p. 869

Pollutants • Substances with which an ecosystem has had no prior evolutionary experience •

Pollutants • Substances with which an ecosystem has had no prior evolutionary experience • No adaptive mechanisms are in place to deal with them

Air Pollutants • Carbon oxides • Sulfur oxides • Nitrogen oxides • Volatile organic

Air Pollutants • Carbon oxides • Sulfur oxides • Nitrogen oxides • Volatile organic compounds • Photochemical oxidants • Suspended particles

Industrial Smog • Gray-air smog • Forms over cities that burn large amounts of

Industrial Smog • Gray-air smog • Forms over cities that burn large amounts of coal and heavy fuel oils; mainly in developing countries • Main components are sulfur oxides and suspended particles

Photochemical smog • Brown-air smog • Forms when sunlight interacts with components from automobile

Photochemical smog • Brown-air smog • Forms when sunlight interacts with components from automobile exhaust • Nitrogen oxides are the main culprits • Hot days contribute to formation

Thermal Inversion • Weather pattern in which a layer of cool, dense air is

Thermal Inversion • Weather pattern in which a layer of cool, dense air is trapped beneath a layer of warm air cool air warm inversion air cool air Figure 48 -7 Page 870

Acid Deposition • Affects much of eastern North America • Caused by the release

Acid Deposition • Affects much of eastern North America • Caused by the release of sulfur and nitrogen oxides • Coal-burning power plants and motor vehicles are major sources

Fig. 48 -8, p. 871

Fig. 48 -8, p. 871

Ozone Thinning • In early spring and summer ozone layer South America over Antarctica

Ozone Thinning • In early spring and summer ozone layer South America over Antarctica thins • Seasonal loss of ozone is at highest level ever recorded Antarctica Figure 48 -6 Page 870

Effect of Ozone Thinning • Increased amount of UV radiation reaches Earth’s surface •

Effect of Ozone Thinning • Increased amount of UV radiation reaches Earth’s surface • UV damages DNA and negatively affects human health • UV also affects plants, lowers primary productivity

Protecting the Ozone Layer • CFC production has been halted in developed countries, will

Protecting the Ozone Layer • CFC production has been halted in developed countries, will be phased out in developing countries • Methyl bromide will be phased out • Even with bans it will take more than 50 years for ozone levels to recover

Fig. 48 -9, p. 871

Fig. 48 -9, p. 871

Ocean Currents • Upper waters move in currents that distribute nutrients and affect regional

Ocean Currents • Upper waters move in currents that distribute nutrients and affect regional climates Figure 48 -10 Page 872

Rain Shadow • Air rises on the windward side, loses moisture before passing over

Rain Shadow • Air rises on the windward side, loses moisture before passing over the mountain Figure 48. 11 Page 873

Monsoons • A pattern of wind circulation that changes seasonally • Affect continents north

Monsoons • A pattern of wind circulation that changes seasonally • Affect continents north and south of warmwater oceans • Can cause seasonal variation in rains

Coastal Breezes • Breeze blows in direction of warmer region • Direction varies with

Coastal Breezes • Breeze blows in direction of warmer region • Direction varies with time of day Afternoon Night

Biogeographic Realms • Six areas in which plants and animals are somewhat similar •

Biogeographic Realms • Six areas in which plants and animals are somewhat similar • Maintain their identity because of climate and physical barriers that tend to maintain isolation between species

Biomes • Regions of land characterized by habitat conditions and community structure • Distinctive

Biomes • Regions of land characterized by habitat conditions and community structure • Distinctive biomes prevail at certain latitudes and elevations

Soil Characteristics • Amount of humus • p. H • Degree of aeration •

Soil Characteristics • Amount of humus • p. H • Degree of aeration • Ability to hold or drain water • Mineral content

Soil Profiles • Layer structure of soil • Soil characteristics determine what plants will

Soil Profiles • Layer structure of soil • Soil characteristics determine what plants will grow and how well Rainforest Desert Grassland Figure 48. 13 Page 876

Fig. 48 -14 a, p. 877

Fig. 48 -14 a, p. 877

Fig. 48 -14 b, p. 877

Fig. 48 -14 b, p. 877

Fig. 48 -15, p. 877

Fig. 48 -15, p. 877

Deserts • Less than 10 centimeters annual rainfall, high level of evaporation • Tend

Deserts • Less than 10 centimeters annual rainfall, high level of evaporation • Tend to occur at 30 degrees north and south and in rain shadows • One-third of land surface is arid or semiarid

Fig. 48 -16, p. 878

Fig. 48 -16, p. 878

Dry Shrublands and Woodlands • Semiarid regions with cooler, wet winters and hot, dry

Dry Shrublands and Woodlands • Semiarid regions with cooler, wet winters and hot, dry summers • Tend to occur in western or southern coastal regions between latitudes of 30 and 40 degrees

Fig. 48 -17 a, p. 879

Fig. 48 -17 a, p. 879

Fig. 48 -17 b, p. 879

Fig. 48 -17 b, p. 879

Fig. 48 -18 a, p. 879

Fig. 48 -18 a, p. 879

Forest Biomes Tall trees form a continuous canopy – Evergreen broadleaves in tropical latitudes

Forest Biomes Tall trees form a continuous canopy – Evergreen broadleaves in tropical latitudes – Deciduous broadleaves in most temperate latitudes – Evergreen conifers at high temperate elevations and at high latitudes

Fig. 48 -19 a, p. 880

Fig. 48 -19 a, p. 880

Fig. 48 -19 b, p. 880

Fig. 48 -19 b, p. 880

Fig. 48 -19 c, p. 880

Fig. 48 -19 c, p. 880

Fig. 48 -19 d, p. 880

Fig. 48 -19 d, p. 880

Fig. 48 -19 e, p. 880

Fig. 48 -19 e, p. 880

Deforestation • Removal of all trees from large tracts of land • 38 million

Deforestation • Removal of all trees from large tracts of land • 38 million acres logged each year • Wood is used for fuel, lumber • Land is cleared for grazing or crops

Effects of Deforestation • Increased leaching and soil erosion • Increased flooding and sedimentation

Effects of Deforestation • Increased leaching and soil erosion • Increased flooding and sedimentation of downstream rivers • Regional precipitation declines • Possible amplification of the greenhouse effect

Regions of Deforestation • Rates of forest loss are greatest in Brazil, Indonesia, Mexico,

Regions of Deforestation • Rates of forest loss are greatest in Brazil, Indonesia, Mexico, and Columbia • Highly mechanized logging is proceeding in temperate forests of the United States and Canada

Reversing Deforestation • Coalition of groups dedicated to saving Brazil’s remaining forests • Smokeless

Reversing Deforestation • Coalition of groups dedicated to saving Brazil’s remaining forests • Smokeless wood stoves have saved firewood in India • Kenyan women have planted millions of trees

Tropical Rain Forests • Have the greatest variety of insects, most bird species •

Tropical Rain Forests • Have the greatest variety of insects, most bird species • Some tropical forest species may prove valuable to humans • Forests are in areas with fast-growing human populations

Arctic Tundra • Occurs at high latitudes • Permafrost lies beneath surface • Nutrient

Arctic Tundra • Occurs at high latitudes • Permafrost lies beneath surface • Nutrient cycling is very slow Arctic tundra in Russia in summer

Alpine Tundra • Occurs at high elevations • No underlying permafrost • Plants are

Alpine Tundra • Occurs at high elevations • No underlying permafrost • Plants are low cushions or mats as in Arctic tundra

Fig. 48 -21 a, p. 883

Fig. 48 -21 a, p. 883

Fig. 48 -21 b, p. 883

Fig. 48 -21 b, p. 883

Desertification • Conversion of large tracts of grassland to desertlike conditions • Conversions of

Desertification • Conversion of large tracts of grassland to desertlike conditions • Conversions of cropland that result in more than 10 percent decline in productivity

Fig. 48 -23, p. 884

Fig. 48 -23, p. 884

Ongoing Desertification • Sahel region of Africa is undergoing rapid desertification • Causes are

Ongoing Desertification • Sahel region of Africa is undergoing rapid desertification • Causes are overgrazing, overfarming, and prolonged drought • One solution may be to substitute native herbivores for imported cattle

Fig. 48 -25, p. 885

Fig. 48 -25, p. 885

Fig. 48 -26, p. 885

Fig. 48 -26, p. 885

Fig. 48 -27, p. 886

Fig. 48 -27, p. 886

Lakes • Bodies of standing freshwater • Eutrophic: shallow, nutrient-rich, has high primary productivity

Lakes • Bodies of standing freshwater • Eutrophic: shallow, nutrient-rich, has high primary productivity • Oligotrophic: deep, nutrient-poor, has low primary productivity Lake Zonation LITTORAL LIMNETIC PROFUNDAL Figure 48. 28 Page 886

Seasonal Overturn • In spring and fall, temperatures in the lake become more uniform

Seasonal Overturn • In spring and fall, temperatures in the lake become more uniform • Oxygen-rich surface waters mix with deeper oxygen-poor layers • Nutrients that accumulated at bottom are brought to the surface

Eutrophication • Enrichment of a body of water with nutrients • Can occur naturally

Eutrophication • Enrichment of a body of water with nutrients • Can occur naturally over long time span • Can be triggered by pollutants

Fig. 48 -29, p. 887

Fig. 48 -29, p. 887

Water Pollutants • • Sewage Animal wastes Fertilizers Pesticides Industrial chemicals Radioactive material Excess

Water Pollutants • • Sewage Animal wastes Fertilizers Pesticides Industrial chemicals Radioactive material Excess heat (thermal pollution)

Fig. 48 -31, p. 889

Fig. 48 -31, p. 889

Wastewater Treatment • Primary treatment – Use of screens and settling tanks – Addition

Wastewater Treatment • Primary treatment – Use of screens and settling tanks – Addition of chlorine to kill pathogens • Secondary treatment – Microbes break down organic matter • Tertiary treatment removes additional toxic substances; rarely used

Fig. 48 -33 b, p. 890

Fig. 48 -33 b, p. 890

Estuary • Partially enclosed area where saltwater and freshwater mix • Dominated by salt-tolerant

Estuary • Partially enclosed area where saltwater and freshwater mix • Dominated by salt-tolerant plants • Examples are Chesapeake Bay, San Francisco Bay, salt marshes of New England

Sandy Coastlines • Vertical zonation is less obvious than along rocky shores • Detrital

Sandy Coastlines • Vertical zonation is less obvious than along rocky shores • Detrital food webs predominate

Fig. 48 -35, p. 891

Fig. 48 -35, p. 891

Coral Reefs Fig. 48 -36 a, p. 891

Coral Reefs Fig. 48 -36 a, p. 891

Coral Reefs Fig. 48 -36 b, p. 891

Coral Reefs Fig. 48 -36 b, p. 891

Hydrothermal Vents • Openings in ocean floor that spew mineral-rich, superheated water • Primary

Hydrothermal Vents • Openings in ocean floor that spew mineral-rich, superheated water • Primary producers are chemoautotrophic bacteria; use sulfides as energy source Tube worms at hydrothermal vent Figure 48 -38 Page 893